Device for tensioning the mounting sheet onto printing machines

ABSTRACT

A CYLINDER HAVING A COARSE SURFACE AND PIVOTABLY MOUNTED ADJACENT TO THE DRUM OF A PRINTING MACHINE SO THAT THE CYLINDER CAN BE URGED AGAINST THE MOUNTING SHEET RETAINED ON THE DRUM TO SMOOTHEN OUT AND TENSION THE MOUNTING WHEN THE DRUM IS ROTATED AGAINST THE CYLINDER. A RATCHET CATCH IS ALSO PROVIDED FOR HOLDING THE CYLINDER OUT OF CONTACT WITH THE DRUM WHEN IT IS NOT IN USE.

oct. 26;?1497'31 H. BRECHTEL 3,614,926 DEVIYCEfFOR TENSICNING THEMOUNTING y-"SHEET ONTO PRINTING MACHINES med oct. 15, 195s f ff.. 5A

, Inventor.' HE m1 BRECHTELL .By MAQ AUnited States Patent O1 PatentedOct. 26, 1971 U.S. Cl. 101-1 3 Claims ABSTRACT OF THE DISCLOSURE Acylinder having a coarse surface and pivotably mounted adjacent to thedrum of a printing machine so that the cylinder can be urged against themounting sheet retained on the drum to smoothen out and tension themounting when the drum is rotated against the cylinder. A ratchet catchis also provided for holding the cylinder out of contact with the drumwhen it is not in use.

This invention relates generally to a device for tensioning the mountingonto printing machines. More specifically, this invention relates to adevice for stretching mountings onto printing machines which producelarge size paper prints.

Normally with printing machines which produce large size paper prints,at least two persons are needed for putting the mounting onto themachine in a wrinkle free condition. One of the persons is usuallyneeded to move the machine while the other is needed to smooth themounting in a wrinkle free condition onto the machine. During suchmanual operation, it is often found that the mounting is not evenlytensioned around the total width of the printing drum. When this occurs,the hardness of the mounting becomes uneven so that the printing becomesinconsistent on the paper print.

In order to overcome the aforementioned disadvantages of conventionalmountings, this invention provides a device which effects a fool proof,wrinkle free mounting and tensioning of the mount, so that only oneperson is needed to mount and service the printing machine.

The device is provided adjacent to, and parallel to the upper surface ofthe printing drum and adjacent its retaining means. 'Ihe smootheningdevice is provided with a coarse surface, preferably plush, whichengages the upper surface of the printing press drum.

In its preferred embodiment, the smoothening device is maintain in aposition away from the printing press drum by means of a ratchet. Thecoarse surface of the smoothening device may be tensioned together withan intermediate elastic layer disposed on the smoothening device.

In `a further embodiment, the stationary cylinder mayv be moved along alongitudinal axis after loosening its arresting nuts.

IIt is therefore an object according to the present invention to providea smoothening device for conventional printing machines which appliesthe mounting to the printing drum in a wrinkle free condition.

It is another object according to the present invention to provide asmoothening device for printing drums which permits the mounting to beapplied to the printing machine by a single operator.

It is still a further object according to the present invention toprovide a smoothening device for use on printmachines which is simple indesign, easy to manufacture and install, and reliable in operation.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in connection withthe accompanying drawing which discloses the embodiments of the presentinvention. It should be understood, however, that the drawing isdesigned for the purpose of illustration only and not as a denition ofthe limits of the invention as to which reference should be made to theappended claims.

In the drawing wherein similar reference characters denote similarelements throughout the several views:

FIG. 1 is a side view partly in cross-section of the device of theinvention; and

FIG. 2 is a cross-sectional view of the cylinder taken along sectionII-II of IFIG. l.

Referring to FIG. 1, there is shown the device for tensioning andsmoothening the mounting onto a printing press drum 6. The device isshown positioned away from printing press drum 6. If a new mounting isto be applied onto the printing press drum, lthe device and stationaryor non-rotatable cylinder 1 is moved into the position indicated by thebroken line in FIG. l. To pivot cylinder 1 into its broken lineposition, the cylinder is mounted by means of a pivot bolt 2 on alateral support 3 which in turn is supported by an adjustable abutment4. Thus, one merely lifts the ratchet catch 16' off of ratchet pin 16a,thereby permitting support brackets 8 to pivot about bolt 2. Inconstruction, ratchet catch 1'6. extends outwardly from lateral support'3 by means of threaded screw stud 16b. Cylinder 1 is applied onto thesurface of printing press drum `6 at a position following retainingmeans 5, and smoothens or flattens rubber mounting cloth or sheet 7during movement of printing press drum 6 by a single operator in thedirection of the arrow (FIG. 1). Cylinder 1 is sufficiently wide toengage the entire width of mounting sheet 7.

As can be seen in FIG. 2, cylinder 1 is mounted on a pair of parallelsupport brackets 8 by means of stationary trunnion bolts 9 and 10.Cylinder body 11 is mounted so that end portions 12 receive bolts 9l and10, and are retained by axial nuts 1G, so that lateral and rotationalmovement is impossible. However, the position of cylinder body 11 is`adjustable along bolts 9 and 10 by loosening retaining nuts 13. Anelastic intermediate layer 14 is mounted over the cylinder body and iscovered by a coarse layer 15, preferably plush for contact with thesurface of mounting 7.

After rubber cloth 7 is smoothened and tensioned, cylinder 1 ispivotably retracted away from printing press drum 6 and mounted againstlateral support 3 by means of ratchet catch 16. Nuts 113 can be loosenedto permit a new portion of surface 15 to engage mounting 7 if the oldportion becomes worn.

While only a single embodiment of the present invention has been shownand described, it will be understood that many changes and modificationsmay be made thereunto without departing from the spirit and scope of theinvention as dened by the appended claims.

What is claimed is:

1. An apparatus for tensioning and smoothening a, mounting retained on aprinting press drum, comprising:

a pair of parallel spaced-apart support brackets for mounting againstthe printing press;

an elongated axial stud for rotatably supporting said pair of supportbrackets on the printing press;

a non -rotatable cylinder trunnioned on the ends of said supportbrackets, said brackets having a first position for engaging saidcylinder against the mounting of the printing press drum and a secondposition for removing said cylinder from the mounting of the drum;

a catch secured to the printing press for engaging said support bracketsto hold said cylinder in the second position, including a pin extendingoutwardly from one of said pair of support brackets having itslongitudinal axis parallel with the longitudinal axis of said cylinder,said catch having one end mounted to the printing press and including arecess on its other end for engaging said pin; and

a threaded stud rotatably engaging one of said pair of support bracketsso as to provide adjustable abutment of said pair of brackets with theprinting press drum.

2. The apparatus as recited in claim 1, wherein said cylinder comprises;

an axle having its ends trunnioned in the arms of said pair of parallelspaced-apart support brackets,

a cylindrical body portion supported on said axle,

an elastic layer mounted over said body portion, and

a coarse layer mounted over said elastic layer for slidable engagementwith the mounting on the printing press drum.

3. The apparatus as recited in claim 2, wherein said axle includes apair of axial bolts, each having at least one restraining nut threadablyengaging each end of said body portion in order to prevent rotatablemovement of said cylinder about and along its longitudinal axis.

References Cited UNITED STATES PATENTS 8/1923 White 101--177 9/1929Roesen 101-219 X 10/1965 Henkel 101-352 UX 8/1908 Mason lOl-219 10/1934Brawn lOl- 247 7/1936 Finch lOl-409 X 8/1936 Finch lOl-4115 IX 4/1938Hemmerich 38-52 UX 4/1953 McKay 101-329 X 3/1967 Grembecki et al.lOl-425 FOREIGN PATENTS 7/1958 Germany lOl-217 2/1938 Germany lOl-401.3

lOl-415.1

U.S. Cl. XR.

